Fluid motor



Oct. 2, 1962 M. R. SIMMONDS 3,056,378

FLUID MOTOR Filed Feb. 1, 1960 2 Sheets-Sheet l 77 7'7 22 50 I 26 :2 @v i 30 I INVENTOR BY Q MM ATTORNEXE,

Oct. 2, 1962 M. R. SIMMONDS 3,056,378

FLUID MOTOR Filed Feb. 1, 1960 2 Sheets-Sheet 2 g .5 it; Q

ATTORNEY-i 3,056,378 Patented Oct. 2, 1962 3,5,37$ FLUED MGTQR Milo Simmonds, Wiliiamsville, N321, assignor to var-d H. Replogle, Snyder, N.Y. ti Feb. 1, llf'fifi, Ser. No. 5,985 17 Clairns. (til. 116-70) This invention relates to a tluid motor and more particularly to an embodiment of the same in a low pressure warning alarm.

The principal object of the present invention is to provide a fluid motor having a reciprocable actuator which may be operatively utilized where desired.

A more specific object of the present invention is to embody the fluid motor in apparatus used to sense the ressure being sensed falls to a predetermined level so as to permit the fluid motor to actuate a suitable signal device such as by striking a bell to give a continuously ringing, audible alarm signal.

Another object is to provide such a low pressure warning alarm which is fully automatic in operation.

Another object is to provide such an alarm which can be selectively preset to sound the alarm signal at the desired low pressure setting.

A further object is to provide such an a negligible amount of fluid.

Still another object is to provide such an alarm which automatically resets itself when the pressure sensed is restored to above the predetermined level.

Other objects or" the invention are to provide such an apparatus and fluid motor which is compact in size, light in weight, simple in construction and therefore relatively inexpensive to manufacture, and which is unlikely to get out of order or require repair.

Still further objects and advantages will be apparent from the accompanying detailed description of a preferred embodiment of the invention and which is illustrated in the accompanying drawings wherein FIG. 1 is a view partly in elevation and partly in section of a low pressure warning alarm constructed in accordance with principles of the present invention.

FIG. 2 is a sectional view thereof taken on line 2-2 of FIG. 1 and illustrates the condition of certain parts when the pressure being sensed is above a predetermined level.

FIG. 3 is a sectional view of FIG. 2 and illustrates the when the level.

FIGS. 4 through 7 severally are enlarged fragmentary sectional views of the right hand portion of the device illustrated in FIG. 2 and showing the position of various movable parts of the valve and motor sections to depict the operation of the device.

-he low pressure warning alarm is shown as having a generally squat T-shaped body It the cross bar portion of which is provided with a cylindrical through bore 11 enlarged at one end as indicated at 12 the outer portion of which is formed with internal threads 13, and the other end of which is enlarged as indicated at 14 the outer end portion of which is formed with internal threads 15. The leg portion ill of the body is s shown as formed to provide a through passage 16 counterbored about one half its length, the outer end portions of the bore 16 being formed with female pipe threads to receive severally the alarm which uses thereof taken on line 33 condition of certain parts pressure being sensed is below a predetermined Typically, the present novel alarm may be arranged in the supply line between the compressed air tank and pressure regulator of self-contained breathing equipment worn by persons working in an undesirable atmosphere such as firemen, mine workers, etc. In such equipment (none of which is illustrated in the accompanying draw- 17 which is tightly by the difference in diameter between the bore 11 and its counterbore 14, as shown in FIG. 3. The place of communication of passage 22 with shoulder 23 is adjacent the corner between this shoulder and the body bore 11.

Internally the body 10 is formed to provide first, second and third chambers 24, 25 and 26, respectively. The

face of the transverse end wall 2% of a cup-shaped member 30 arranged on the counterbore 14.

The chamber 25 is formed by the cup-shaped recess of the member 30 and the transverse end wall 31 of a barrel member '32 also arranged in the counterbore 14. The

Which a sealing ring 35 such as a rubber O-ring is arranged and adapted to engage the opposing wall surface of the counterbore 14. The inner end face of the end wall 31 abuts against the rim 30 of the cup-shaped member 30. The periphery of this cup-shaped member 30 is also cylindrical and closely fits the counterbore 14. The radially outer corner of the inserted end of the cup-shaped member 30 is cut out annularly and accommodates a seal ring 36 such as a rubber O-ring which bears against the shoulder 23. The inner end face 3i) of the cup-shaped member 30 inwardly of the O-ring 35 also bears against the shoulder 23.

Holding the barrel member 32 axially against the cupshaped member 39 which in turn is held against the shoulder 23 of the body lid is an annular barrel retainer 38. Externally this retainer 38 is formed with male threads 39 which are received in the female threads 15 of the body 10. Centrally the retainer 38 has a stepped bore 4%) reduced at its outer end as indicated at 41 to provide an inwardly and axially facing shoulder 42 therebetween. The inner end of the bore 40 is enlarged as indicated at 43 to provide therebetween an inwardly facing annular shoulder 44. The shoulder 44 abuts against the outer and axially facing end face 45 of the barrel member 32.

The chamber 26 is provided by a cylinder 46 formed internally and centrally in the barrel member 32 and shown as having the same diameter as the bore 46 in the retainer 38. The end of this cylinder 46 at its inner end is defined by the annular radial end wall 43 which surrounds an annular raised roundnosed seat 4 9. This seat 49 projects into the chamber 26 and surrounds the passage 34 interconnecting the chambers 25 and 26. The other end of the chamber 26 is defined by the inner end face of the enlarged cylindrical head of a plunger or piston member 51. The cylinder 46 and the bore 40 are shown as being co-extensive to provide jointly an annular space surrounding the plunger or piston member 51. Arranged in this space is a helical compression spring 52, the inner end of which bears against the outer end face 50 of the piston head 50 and the outer end of which bears against the inwardly facing shoulder 42.

The outer end portion of the plunger or piston member 51 is shown as being reduced in diameter as indicated at 53 so as to be slidable through the reduced bore 41 in the barrel retainer member 33. The opposite end or inner end of the plunger or piston member 51 is shown as formed with a cylindrical recess 54 which receives and holds a solid cylinder or plug 55 of rubber or the like. This plug 55 may be press-fitted in or cemented to the Walls of the recess 54. The outer portion of this rubber plug 55 is shown as extending axially outwardly beyond the inner end face 51? of the piston head 59. The exposed end face 56 of the rubber plug 55 is adapted to engage the annular seat 4 Arranged adiacent the end wall 48 of the cylinder 46 but axially spaced outwardly therefrom is a plurality of outwardly extending and circumferentially spaced passages or exhaust ports 58. These ports 58 lead from the cylindrical wall 46 to an annular space 59 provided between the spaced and opposing end surfaces of the end wall 31 and the retainer member 38. The annular space 59 is placed in communication with the atmosphere external to the body by a series of axially extending and circumferentially spaced vent holes or passages 60 formed in the retainer member 38 and extending completely therethrough.

It will be seen that if a fluid such as compressed air within the intermediate chamber 25, builds up to a suiticient pressure, the force acting against the exposed area of the piston end face 56 will drive the plunger or piston member 51 to the right as viewed in the various figures, against the urging of the return spring 52. The outer end portion of the plunger or piston member 51 serves as a striker adapted to engage a cup-shaped bell 61 which is suitably supported on the body it? as by a pair of screws 62. The bell 61 is shown as having an annular shirt in the path of outward travel of the plunger or piston member 51.

Valve means are provided for controlling the admission of fluid from the chamber 24 into the chamber 25 through the restricted orifice 3 While any suitable means may be employed for this purpose, that shown comprises a dished disk or circular diaphragm 63. This diaphragm 63 is preformed into substantially the bowed or dished configuration shown in FIGS. 2 and 4. The diaphragm is arranged in the chamber 24. More specifically, it is accommodated in a cylindrically walled recess 67 formed in the end wall 29 of the member 3% on the side thereof opposite from the chamber 25. The central salient part of the diaphragm 63 on the convex side thereof is shown as carrying a closure pad 64 made of rubber or other suitable slightly resilient material. The pad 64 is preferably cemented to the diaphragm 63. The exposed end face of this closure pad 64 is adapted to engage an annular round-nosed seat 65 surrounding the end of the restricted orifice 33 remote from the chamber 25. Surrounding this annular seat 65 is a slightly recessed annular radially extending surface 66.

The marginal portion of the diaphragm 63 is adapted to be clamped between opposing inclined surfaces 65 and 69 formed on the end wall 29 of the cup-shaped member 30 and the enlarged head portion of the plunger 28, respectively. The clamp surfaces 68 and 69 are severally of a frusto-conical configuration, being inclined radially inwardly and axially away from the chamber 25 so that as the surfaces approach each other the diaphragm 63 is forced to bend or flex from the position shown in FIG. 2 to the position shown in PEG. 3. The angle of the inclined surfaces 68 and 6? to a transverse plane perpendicular to the direction of movement of the plunger 28, is preferably 5. The central portion of the plunger 28 at the same end is shown as having a recess 7% to accommodate the central portion of the diaphragm 63 when it is flexed into the position shown in FIG. 3. The diaphragm 63 is shown as provided with a pair of holes 71 on opposite sides of the closure pad 64 so as to provide for movement of fluid from one to the opposite side of the diaphragm. The plunger 28 is shown as having an annular groove '72 at the base of the annular axially facing shoulder 73 on the plunger. A pair of holes 74 are shown in the plunger as extending between the annular groove 72 and the recessed surface 70.

The pressure of the fluid within the chamber 24 urges the plunger to the left as viewed in FIGS. 2 through 7, or away from the diaphragm 63, and if the pressure in this chamber 24 is sufficiently high, the shoulder 73 on the plunger will engage the end wall 23 on the body it). This limits the outward movement of the plunger. The plunger 23 is urged to move in the opposite direction, or toward the diaphragm 63, by a helical compression spring 75 engaging a spring support washer 76 fitted on the reduced end of the plunger 28 and bearing against the shoulder 77 thereon. The opposite end of the spring 75 bears against a spring retainer 73 which is in the nature of a plug provided externally with male threads received in the female thread 13 at the outer end of the counterbo-re 12. The outer end face of the spring retainer 78 is shown as provided with a slot 79 adapted to receive a tool (not shown) such as a screw driver. By turning the spring retainer 78, the initial compression of the spring 75 can be adjusted as desired.

The plunger 28 is sealed by a seal ring 3i such as a rubber O-ring arranged in an annular groove provided in the body of the plunger 28 and engaging the Wall of the bore 11. This prevents blow-by of fluid from chamber 24.

Operation Assuming fluid under pressure, such as compressed air, is flowing or present in the duct including the pipes 18 and 19 and has a value above the predetermined level below which the alarm is actuated. The fluid pressure is transmitted from the duct, through filter element 2') into annular chamber 27, through the passage 22, annular groove 72 and holes 74 to the chamber 24. The pressure is felt on opposite sides of the diaphragm 63 arranged within this chamber because of the holes 71 in the diaphragm. With the pressure in chamber 24 above the value required to actuate the alarm, the pressure is effective to hold the shoulder of the plunger 2% in abutting engagement with the body shoulder 23, against the urging of the spring 75. This condition of the parts is depicted in FIGS. 2 and 4. It will be noted 28 and its salient part toward its seat 65.

When the alarm is in the condition depicted in FIGS. 2 and 4, it will be seen that the spring 52 is holding the the pneumatic force against the plunger 28 permits the spring 75 to expand and drive the to the position shown in FIG. 5. Because of its performed dished condition, the diaphragm 63 Snaps from one position to the other as its margin central portion.

inlet to the and definite The pressure within this chamber 25 builds up and is eflective against the exposed area of the end face 56 of the plunger or piston member 51. The exposed area between the salient of the annular seat 49 and the piston end face 56. When the pressure within the chamber 25 and effective against such exposed face area has in d as a quickly to the right.

As the plunger or piston member 51 continues to move to the right, its outer end will strike the bell 61, as depicted in FIG. 7. As this occurs, the head 50 of the plunger or piston member uncovers the exhaust ports 58 allowing the residual pressure of the fluid in the interconnected chambers 25 and 26 to be exhausted to the atmosphere, the exhaust fluid flowing outwardly through the exhaust ports 58, annular space 59 and holes 60. Such sudden dissipation of the pressure within the chamber 26 renders the return spring 52 eflective to move the plunger or piston member 51 from right to left or from the position to the position shown with the parts in the chamber 25 Will refill with fluid under pressure but relatively slowly since the incoming fluid must pass through the restricted inlet port 33. Typically, this orifice 33 may have a diameter of .006 inch and the filter element 20' protects such a small opening irom becoming clogged with solid particles.

previously explained so as to strike the In this manner, as long as the restricted is maintained opened, as by holding the diadomg so strike the bell upon each stroke of the plunger or piston member 51. Everything else being equal and within limits, varying the diameter of the restricted orifice 33 changes the cyclic rate of reciprocation of the plunger or piston member 51. The larger the diameter, the higher the rate since the chamber 25 Will fill more quickly, and vice versa.

Thus the repeated striking of the bell 61 produces an audible alarm signal which advises that the pressure being sensed has fallen to a predetermined level. The plunger or piston member 51 Will continue to reciprocate as explained above until the maximum pressure developed in the intermediate chamber 25 is lIlSllfilCl6I1t to unseat the plunger or piston member 51. In other words, there is predetermined level, between the extremes of which the plunger or piston member '51 reciprocates.

The value of the pressure below which the plunger or piston member 51 will reciprocate is determined by the adjustment of the spring retainer '78. By screwing this retainer farther into the body lit so as to compress the spring 75 more, the higher than that of the chamber 26 even when the plunger or piston member 51 is unseated and in a position uncovering the exhaust ports 58, as shown in FIG. 7.

The means providing the chamber 25' with its restricted ports 53, motor. The diaphragm 63 and the associated mechanism such as the plunger 28 and spring 75 constitutes a valve section. The motor section as above defined may be associated with a specifically different valve means than that described above.

From the foregoing, it will What is claimed is:

1. In a fluid motor, the combination comprising means providing a chamber, means providing a cylinder, means providing a passage interconnecting said chamber and cylinder and serving as an inlet port for said cylinder, means providing a restricted inlet orifice for said chamber, means providing an exhaust port for said cylinder, a piston member reciprocably arranged in said cylinder and closing ofl said inlet port and blocking said exhaust port but adapted to be moved by fluid entering said inlet port to uncover said exhaust port, and yieldable means urging said member to close ofl said inlet port.

spasms providing an exhaust port for said cylinder adjacent but axially spaced from said one end thereof, a piston member reciprocably arranged within said cylinder between one position in which said exhaust port is covered by the periphery of said member and said seat is engaged by one end of said member to close ofi said passage and a second position in which said exhaust port is uncovered and said seat is disengaged to uncover said passage, and yieldable means constantly urging said member toward said seat.

3. In a fluid motor, the combination comprising means providing a chamber, means providing a cylinder, means providing a passage interconnecting said chamber and cylinder, means providing a restricted inlet orifice for said chamber, an annular seat Within said cylinder at one end thereof and surrounding said passage, means providing an exhaust port for said cylinder adjacent but axially spaced from said one end thereof, a piston member reciprocably arranged within said cylinder between one position in which said exhaust port is covered by the periphery of said member and said seat is engaged by one end or" said member to close off said passage and a second position in which said exhaust port is uncovered and said seat is disengaged to uncover said passage, and yieldable means constantly urging said member toward said seat, the area of said one end of said member exposed to communication with said chamber when said member engages said seat being less than the full area of said one end of said member, the volume of said chamber being greater than that of said cylinder when said member is in said second position.

4. A low pressure warning alarm for sensing the pressure of fluid in a duct, comprising means providing a chamber, means providing an outlet port for said chamber, a seat surrounding said port on the downstream side thereof, a signal device, a member engaging said seat and adapted to be moved to actuate said signal device, and automatically operated valve means arranged to introduce pressurized fluid into said chamber when the pressure of fluid in said duct falls to a predetermined level.

5. A low pressure warning alarm for sensing the pressure of fluid in a duct, comprising means providing a chamber, means providing an outlet port for said chamher, a seat surrounding said port on the downstream side thereof, a bell, a striker engaging said seat and adapted to be moved to strike said bell, and means arranged to introduce pressurized fluid into said chamber when the pressure of fluid in said duct falls to a predetermined level.

6. A low pressure warning alarm for sensing the pressure of fluid in a duct, comprising means providing a chamber, means providing an outlet port for said chamber, a seat surrounding said port on the downstream side thereof, a bell, a striker engaging said seat and adapted to be moved to strike said bell, spring means urging said striker toward said seat, and means arranged to introduce pressurized fluid into said chamber when the pressure of fluid in said duct falls to a predetermined level.

7. A low pressure warning alarm for sensing the pressure of fluid in a duct, comprising means providing, a pair of chambers separated by a wall, said wall having a passage therethrough communicating with said chambers, a portion of said wall surrounding said passage providing a seat, a signal device, a plunger slidably arranged in one of said chambers and engaging said seat and adapted to be moved to actuate said signal device, the end area of said plunger facing said seat being larger than the cross-sectional area of said passage, said areas communicating with each other when said plunger is unseated, and means arranged to introduce pressurized fluid into the other of said chambers when the pressure of fluid in said duct falls to a predetermined level.

8. A low pressure warning device for sensing the pressure of fluid in a duct, comprising means providing a chamber, means providing a cylinder, means providing a passage interconnecting said chamber and cylinder and serving as an outlet port for said chamber, an outlet seat surrounding said outlet port on the cylinder side thereof, a signal device, a plunger slidably arranged in said cylinder and engaging said outlet seat and adapted to be moved to actuate said signal device, means providing a restricted inlet port for said chamber, an inlet seat surrounding said inlet port, a valve for said inlet port, i eans establishing communication between said duct and inlet port when said valve is unseated, and means for unseating said valve when the pressure in said duct falls to a predetermined level.

9. A low pressure Warning device for sensing the pressure of fluid in a duct, comprising means providing first, second and third chambers, means for establishing communication between said first chamber and duct, means establishing restricted communication between said first and second chambers and serving as a restricted inlet port for said second chamber, means establishing communication between said second and third chambers and serving as an outlet port for said second chamber, a signal device, a plunger slidably arranged in said third chamber and closing said outlet port and adapted to be moved to actuate said signal device, a biased valve arranged in said first chamber and normally closing said inlet port, and means operated in response to the pressure of fluid in said first chamber for moving said valve whereby said inlet port is opened when the pressure in said duct falls to a predetermined level.

10. A low pressure warning device for sensing the pressure of fluid in a duct, comprising means providing first, second and third chambers, means for establishing communication between said first chamber and duct, means establishing restricted communication between said first and second chambers and serving as a restricted inlet port for said second chamber, means establishing communication between said second and third chambers and serving as an outlet port for said second chamber, a signal device, a plunger slidably arranged in said third chamber and closing said outlet port and adapted to be moved to actuate said signal device, a flexible bowed valve arranged in said first chamber and having a salient part closing said inlet port, and means for flexing said valve so as to withdraw said salient part and uncover said inlet port when the pressure in said duct falls to a predetermined level.

11. A low pressure warning device for sensing the pressure of fluid in a duct, comprising means providing first, second and third chambers, means for establishing communication between said first chamber and duct, means establishing restricted communication between said first and second chambers and serving as a restricted inlet port for said second chamber, means establishing communication between said second and third chambers and serving as an outlet port for said second chamber, a signal device, a plunger slidably arranged in said third chamber and closing said outlet port and adapted to be moved to actuate said signal device, a biased valve arranged in said first chamber and normally closing said inlet port, and means operated in response to the pressure of fluid in said first chamber for moving said valve whereby said inlet port is opened when the pressure in said duct falls to a predetermined level, said means including a movable member engaging said valve and urged to move away from said valve by the pressure of fluid in said first chamber and spring means urging said member to move toward said valve.

12. A low pressure warning device for sensing the pressure of fluid in a duct, comprising means providing first, second and third chambers, means for establishing communication between said first chamber and duct, means establishing restricted communication between said first and second chambers and serving as a restricted inlet port for said second chamber, means establishing communication between said second and third chambers and serving as an outlet port for said second chamber, a

a predetermined level.

13. A low pressure warning device for sensing the pressure of fluid in a duct, comprising means providing first,

device, a plunger slidably arranged in said third chamber and closing said outlet port and adapted to be moved to actuate said signal device, a flexible bowed valve arsaid inlet port, and spring means urging said member to move toward said valve, the pressure in said duct falls to a predetermined level.

14. A low pressure warning device for sensing the pressure of fluid in a duct, comprising means providing first, second and third charn port for said second chamber, means establishing communication between said second and third chambers and serving as an outlet port for said second chamber, a signal device, a plunger slidably arranged in said third chamber and closing said outlet port and adapted to be moved to actuate said signal device, a dished diaphragm arranged in said first chamber and having a salient closure part closing said inlet port, an annular stationary frusto-conical surface on the side of said diaphragm on which said inlet port is arranged and surrounding said inlet port, a movable member on the opposite side of said diaphragm and having a frusto-conical surface opposite to and spaced from said stationary surface, said surfaces when moved sufficiently close together flexing said diaphragm so as to reverse its bow and withdraw said salient whereby said surfaces move toward pressure in said duct falls to a prepressure of fluid in a duct, the combination comprising level, said valve means including a bowed closure having its salient part closing said inlet port, a movable member engaging said closure on opposite sides of said salient part and spring means urging said movable member toward said closure to flex the same so that said salient part thereof snaps away from said inlet port thereby to uncover the same, the pressure of the fluid in said duct acting upon said movable member in opposition to the urging of said spring means.

16. In a fluid rnotor, the combination comprising supply chamber, means providing a cylinder, means providing a passage interconnect- References Cited in the file of this patent UNITED STATES PATENTS Sauveur Jan. 26, 1915 Ehn Oct. 3, 1933 Disclaimer 3,O56,378.Mi20 R. Simmonds, Williamsville, N.Y. FLUID MOTQR. Patent dated Oct. 2, 1962. Disclaimer filed Aug. 7, 1963, by the assignee, E dward H. Replogle. Hereby enters this disclaimer to claims 16 and 17 of said patent.

[Oficz'al Gazette October 22, 1963.] 

